Death of Rats – a larger-than-life Discworld Decoration

The Death of Rats has been guarding our home against supernatural incursions around Halloween for a few years now, but I finally got around to redoing it with a skeleton and a light show of its own. Let me show you how I made it, so that you can make your own – or something completely different! Please share this with your friends, and remember to be Inspired!

The Future of the Death of Rats

If you have what amounts to be a rat skeleton in black robes, you would want to see the skeleton, right? The original version had the robes closed around a wooden superstructure (and you can check out the Instructable I wrote for Mk. I). You already saw me remake it and add a proper skeleton to it. But there is so much more that I still want to add to this, and if you are curious, I will give you the rundown here. It is also a way to hold myself accountable next Halloween, and the one after that, and… Well, I can always edit this. I might never get to some of those points, but maybe they can inspire you!

The Scythe

The first thing the rat needs – there is no argument about it – is a scythe. The original had one that was made out of a scythe-shaped piece of plastic hot-glued to the very same stick it is now wielding. It looked okay, but I have an idea how to make something much cooler, and I am not telling you.

Wait – what would be the point in that? Of course, I will let you know. My idea is to take two pieces of thin transparent plastic, cut both to a scythe-like shape and connect them along what would be the cutting edge. The idea is to create a thin v-shape, a gap between them that widens towards the top. Between those pieces on the hilt, I want to add some LEDs, possibly with a short sleeve to prevent light from spreading too far too soon. Basically, spectators should not be able to see the LEDs, only their light along the blade.

Now the idea is that this scythe would be pretty unobtrusive if not quite transparent in daylight, and nigh-invisible during the night – unless it was lit. I would expect (or hope for) the plastic to become visible in a ghostly way, with the light getting stronger towards the edge, making it look like one made of pure energy. At least a maker can dream…

The Hourglass

Here, I have two (point five) main ideas. The one is to make a classical Death-themes hourglass, possibly carved and very ornate, with two discs and a number of columns connecting them. For the glass shape, I want to use two acrylic teardrops.

The second half of the idea is to light it up in a way that mimics sand running down. I think that would be doable with a series of LEDs set close to each other, with some diffusing material surrounding them. I am not quite sure how I would want it to look, and I guess I will not know until I see it.

And the half idea is to add a motor that actually turns the hourglass over. That would be cool, and possible, I think, if I can manage to mount it in a stable fashion, but it would require some kind of trigger (see below). Which is why this is only half an idea.

Approach with Caution!

Part of this already worked on the breadboard at some point, but it would have been too time-consuming to implement it this year. The idea is to make the Death of Rats react to its fans.

The first step would be to add a pir module/motion sensor, This would allow the rat to take a break when nobody is watching – better than running on full all night long. I think this would be done by lowering the brightness of the LEDs, so there is a faint light but when something moves that light would “wake up”. Possibly, the eyes would be off and turn on in a blinking fashion akin to the rat waking up.

The pir would be a good addition to the hourglass moving because otherwise, it would be pointless, and there would be no way to determine when to let time run out.

The next addition would be a range sensor to determine when someone is actually coming close.The idea was that the lights illuminating the robes would change from blue-white to blue-yellow and then to red-yellow. The eyes themselves would have flashed or done something fiery, too. That effect actually worked on the breadboard already, but it was not very relyable. I think the main issue here would be the placement of the sensors (which work with ultrasound) and making the function robust against measuring errors.

If you are interested in the technical side, the Arduino would use the average of the last five measurements from the sensor (to even out odd values) to change the color palette the LEDs were running.

Make the Death of Rats come alive

This would be the pinnacle of my rat-related ambitions – add more motors so that the rat can move its head from side to side and possibly nod. Having it open and close its jaw would be awesome, and probably easier than re-mounting the whole head.

With the moving jaw, it would be able to squeak – adding an appropriate noise to it to address passers-by. I am not quite sure yet whether that would actually work, with all the sensors required to make it look good. To begin with, how would the rat know where to look? Or would it look okay if it moved its jaw and “speak” without turning its head? We may never know…

Thanks for stopping by. I am happy with the result of this year’s makeover, and I like to believe that the Death of Rats is, too. Maybe even Sir Terry himself, but I would not go that far. Please share this project, and I hope it inspires you to make something awesome!